The actual international investment regime is composed of an entanglement of international agreements where the bilateral investment treaties (BIT) are prevailing. We count at present around 2500 treaties. After the reoccurring failure of multilateral treaty projects, the profusion of BIT has been often viewed as a second best solution. This contribution examines the hypothesis of "sub-optimality" of BIT. It shows at first that BIT represents a rational strategy for at least one category of countries : those that we call emerging powers. It suggests then that an international regime founded on BIT : a) is not necessarily economically less efficient than a multilateral investment treaty; 2) is more in accordance with the actual distribution of power between developed countries, emerging countries and the other developing countries. It seems therefore that the hypothesis founded on the superiority of multilateralism is not validated in the field of investment.
